This relates to an apparatus for determining the shot pattern of a shotgun or accuracy of a rifle or other gun shooting bullets. The pattern which the shots of a shotgun make is most important to a hunter. The pattern for a particular shotgun can mean the difference between either hitting or missing the target. It is important to know the shot pattern for the particular shot and load to be used by the hunter for a particular gun. It is of course necessary to properly calibrate a rifle for accurate shooting.